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Sorry to kind of hijack this thread, but I was thinking of something somewhat related.

Would a hard start kit work on a fan motor? Say its 4 pm on Friday and you find an important piece of equipment that has a seized up psc fan motor. You spin the motor with your hand and it takes off and keeps going, but you know it will just seize up again next time it tries to start. Would the hard start kit have any chance of helping in this situation, to maybe get you through the night or weekend?

Sorry to kind of hijack this thread, but I was thinking of something somewhat related.

Would a hard start kit work on a fan motor? Say its 4 pm on Friday and you find an important piece of equipment that has a seized up psc fan motor. You spin the motor with your hand and it takes off and keeps going, but you know it will just seize up again next time it tries to start. Would the hard start kit have any chance of helping in this situation, to maybe get you through the night or weekend?

I doubt it!!!!! Maybe a bigger cap might do it. I have occasionally kept them going overnight by running the thing constant one I got it started.

ammoniadog Sorry to kind of hijack this thread, but I was thinking of something somewhat related.

Would a hard start kit work on a fan motor? Say its 4 pm on Friday and you find an important piece of equipment that has a seized up psc fan motor. You spin the motor with your hand and it takes off and keeps going, but you know it will just seize up again next time it tries to start. Would the hard start kit have any chance of helping in this situation, to maybe get you through the night or weekend?

Yes

Good Things Come To Those Who Wait, But Only the Things Left Over By Those Who Hustle.

i am a fan of the properly sized 5-2-1 hard start kit. the relay must be in the correct position. there has been big debates on putting a hard start on a scroll. rheem has put them on scrolls since the beginning. if you think about it a scroll has a motor just like a recip does or a rotary. its a motor so put a 5-2-1 on it and be done. any system that has a hard shutoff expansion valve should also have a real 5-2-1 hard start.

if you have intermittent breaker trips then i would look for a couple other things as well;
1. a crankcase heater that has a broken band
2. loose wires on the peckerhead
3. fan motor that randomly over heats
4. dirty condenser coil
5. intermittent shorting motor(megaohm the compressor)

i am a fan of the properly sized 5-2-1 hard start kit. the relay must be in the correct position. there has been big debates on putting a hard start on a scroll. rheem has put them on scrolls since the beginning. if you think about it a scroll has a motor just like a recip does or a rotary. its a motor so put a 5-2-1 on it and be done. any system that has a hard shutoff expansion valve should also have a real 5-2-1 hard start.

if you have intermittent breaker trips then i would look for a couple other things as well;
1. a crankcase heater that has a broken band
2. loose wires on the peckerhead
3. fan motor that randomly over heats
4. dirty condenser coil
5. intermittent shorting motor(megaohm the compressor)

Good info but Rheem or in my case Ruud has not been installing them on the units I have purchased for some time now. This was part of the reason I was concerned about installing them on scrolls as they have not been shipping with start components.

Good info but Rheem or in my case Ruud has not been installing them on the units I have purchased for some time now. This was part of the reason I was concerned about installing them on scrolls as they have not been shipping with start components.

this might be why rheem/ruud is quoted cheaper to me then trane. is this whith their base equipment or all equipment?

AS/Trane factory installs start assist kits on their heat pumps with scroll compressors, and has called for the addition of them to scroll equipped AC units, used for low ambient cooling, for a number of years.
Since scroll compressors have more mechanical friction than recips to overcome when starting, they use larger motors, with higher LRA, than similar capacity recip compressors.
Because of the higher start-up current, the motors in scroll compressors, as well as the contactor, etc., benefit from start assist components even more than recips.
This is especially true when the compressor is cold, due to the increased friction from the oil thickening, and contraction of the metal parts.

I think some of the "debate" over hard start kits on scrolls stems from past, maybe current, cautions from various sources about using them on scroll compressors that have mechanical problems that cause them to stick.
Those cautions have often been strongly worded, or even labeled as warnings.

It has always been common with mechanically stuck recip compressors to get more life out of them by installing a hard start kit when one is found not starting due to a mechanical issue. It can't hurt to try it, and compressors often run that way for years.

Scroll compressors are mechanically very different than recips, and due to the nature of how the scroll mechanism works, and the tight tolerances, just need to be replaced if they are mechanically sticking enough to not start without a start assist.

Adding a start kit to eek some more life out of a recip with mechanical issues typically won't result in anything worse than further mechanical damage.
Adding a start kit to a scroll compressor with mechanical damage is a high probability path to a burnout.

Never hesitate to add a proper start assist to a scroll compressor to reduce light dimming due to voltage drops on startup, and/or stress on the motor windings, or to help with starting in very low ambient temperatures.
I wouldn't install one on a scroll compressor that is mechanically stuck though, unless it is just to get it going for a day or two until you get back out to replace it.

this might be why rheem/ruud is quoted cheaper to me then trane. is this whith their base equipment or all equipment?

i have found many scrolls that needed hard start kits

I'm finding they may with these new coils that do not equalize. I typically install their 13 seer rectangle units and they have not been coming with start components. A few years ago when the 13 was the next up in line they did come with them. At that time I was under the impression that they were added along with a HP cutout because they carried a ten year parts/compressor over the 1/5 on the base model.
I guess in the end its always cost. The same reason they start putting in contactors for 15 cents less then the ones with nice lugs!

AS/Trane factory installs start assist kits on their heat pumps with scroll compressors, and has called for the addition of them to scroll equipped AC units, used for low ambient cooling, for a number of years.
Since scroll compressors have more mechanical friction than recips to overcome when starting, they use larger motors, with higher LRA, than similar capacity recip compressors.
Because of the higher start-up current, the motors in scroll compressors, as well as the contactor, etc., benefit from start assist components even more than recips.
This is especially true when the compressor is cold, due to the increased friction from the oil thickening, and contraction of the metal parts.

I think some of the "debate" over hard start kits on scrolls stems from past, maybe current, cautions from various sources about using them on scroll compressors that have mechanical problems that cause them to stick.
Those cautions have often been strongly worded, or even labeled as warnings.

It has always been common with mechanically stuck recip compressors to get more life out of them by installing a hard start kit when one is found not starting due to a mechanical issue. It can't hurt to try it, and compressors often run that way for years.

Scroll compressors are mechanically very different than recips, and due to the nature of how the scroll mechanism works, and the tight tolerances, just need to be replaced if they are mechanically sticking enough to not start without a start assist.

Adding a start kit to eek some more life out of a recip with mechanical issues typically won't result in anything worse than further mechanical damage.
Adding a start kit to a scroll compressor with mechanical damage is a high probability path to a burnout.

Never hesitate to add a proper start assist to a scroll compressor to reduce light dimming due to voltage drops on startup, and/or stress on the motor windings, or to help with starting in very low ambient temperatures.
I wouldn't install one on a scroll compressor that is mechanically stuck though, unless it is just to get it going for a day or two until you get back out to replace it.